Life Sciences Grade 12 NSC P1 QP September 2025 Mpumalanga

education MPUMALANGA PROVINCE REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P2 SEPTEMBER 2025 MARKS: 150 Copyright reserved These marking guidelines consist of 13 pages. Please turn over

Life Sciences/P1 M NSC DE/September 2025 INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. 2. 3. 10. zie Answer ALL the questions. Write all the answers in the ANSWER BOOK. Start the answers to EACH question at the top of a NEW page. Number the answers correctly to the numberin paper. g system used in the question Present your answers according to the instructions of each question. Do ALL drawings in pencil and label them in blue or black ink. Draw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. Do NOT use graph paper. You must use a non-programmable calculator, protractor and a compass, where necessary. Write neatly and legibly.

Life Sciences/P1 3 MDE/September 2025 Nsc SECTION A QUESTION 1 1.1 Various options are provided S i i uesti Chceme te wees as possible answers to the following questions. and write only the letter (A to D) next to the question number (1.1.1 to 1.1.10) in the ANSWER BOOK. for example 1.1.11 D. 1.1.1. Which of the following involves the development of the young inside the uterus of the mother, where it receives nutrients through the placenta? A Ovipary B-Ovovivipary /C Vivipary D Amniotic egg 1.1.2 Sperm cells in humans are temporarily stored: A Ovary /B Epididymis Cc Vas deferens D Prostate gland 1.1.3 The diagram below shows a stage of gestation One of the functions of part Ais to... A __ serveas a reserve food supply. B give rise to the placenta. revent the developing foetus from moving about. : D antes the fluid that protects the embryo against injury. Please turn over Copyright reserved

‘e Sciences/P1 MDE/September 2025 NSC 1.1.4. Which ONE of the following are functions of adrenalin? 4.1.5 1.1.6 A “B Cc D Influences the pupil size and controls the amount of water lost by the body through the kidneys. increases the blood sugar level and blood pressure. Decreases metabolic rate and blood sugar level. Affects growth and increases muscle tone. An investigation was done to determine the effect of alcohol on the reaction time of a person. Reaction time was measured by the time it took to catch a ruler. The procedure was as follows: The person's reaction time was first measured in a room with bright light. The person was then given 200 mf of alcohol to drink. After 15 minutes the reaction time of the person was measured for the second time while he/she was in a room with dim light. Ten measurements were recorded each time, and an average was calculated. How was the validity of the investigation decreased? GDOU>D Reaction time was measured in different light conditions. Only ten measurements were recorded. Reaction time was measured by the time it took to catch a ruler. The person's reaction time was measured in the absence of alcohol the first time. Which of the following pair combinations are plant growth hormones? A B Cc 2D ADH and gibberellins Abscisic acid and glucagon Prolactin and abscisic acid Gibberellins and abscisic acid

Life Sciences/P1 5 MDE/September 2025 NSC 1.1.7 The diagram below represents a growing tip of a coleoptile (youn plant shoot) exposed to unilateral ight. 9 tip ptile (young Growing tip of a coeloptile ‘Noy a aio Unilateral light Which ONE of the following diagrams A, B, C or D correctly represents the direction of growth of the coleoptile after a week? a AL B c D 1.1.8 During periods when the temperature is high, ... the aldosterone levels are expected to be low. the blood vessels on the skin dilate. the adrenalin levels are expected to be high. sweating decreases. 0V0OWUY Please turn over Copyright reserved

MDE/September 2025 Life Sciences/P1 he QUESTIONS 1.1.9 and 1.1.10 are based on the graph below which _ saad as a spirometer trace and is used to determine the volume of a a ne * i S and exhales, as well as their breathing rate (the number of brea period of time). Exercise Volume Time 1.1.9. The spirometer trace shows that exercise causes the ... breathing rate to increase while breathing depth decreases. breathing rate to decrease while breathing depth increases. breathing rate and breathing depth to increase. breathing rate to increase while breathing depth remains constant. vomw>r 1.1.10 Which of the following is responsible for the change in the spirometer trace during exercise? VA Increased energy required by muscle cells B Decrease in the carbon dioxide levels in blood C Decreased respiration in muscle cells D_ Increase in the pH levels of blood (10 X 2) (20) Copyright reserved Please turn over

Life Sciences/P1 1.2 Give the correct bio Write only the term 7 MDE/September 2025 NSC logical term for each of the following descriptions. next to th i ; 1.2.10) in the ANSWER BOOK. © question number (1.2.1 to ) 41241 1.2.2 1:23 1.2.4 125 1.2.6 1.2.7 1.2.8 1.2.9 1.2.10 The hormone which is responsible for development of secondary sexual characteristics j nmales ~ Cyclical events taking place in the ovary Coiled tubular Structure that stores sperm The increase of the internal diameter of blood vessels so that more blood flows through them The growth response of a plant to in response to an external stimulus A hormone that stimulates the mammary glands to produce milk The part of the brain that controls the carbon dioxide levels in the blood The hormone secreted by the thyroid gland that controls the metabolic rate The part of the peripheral nervous system that controls involuntary actions The secretions that are produced in small quantities by the endocrine glands (10x41) (10) Please turn over Copyright reserved

Life Sciences/P1 1.3 8 MDE/September 2025 NSC ts in COLUMN | applies to NE of the items in COLUMN II. Write xt to the question number (1.3.1 to Indicate whether each of the statemen A ONLY, B ONLY, BOTH A AND Bor NO A only, B only, both A and B or none ne 1.3.4) in the ANSWER BOOK. COLUMN | COLUMN II 1.3.1. Receptor in the ear that detects A: Organ of Corti position of the head in space B: Rods 1.3.2 Defence mechanism in plants A: Leaves B: Thorns 1.3.3 A Hormone that stimulates an increase | A: Insulin in the blood glucose level B: Glycogen 1.3.4 The human pancreas functions as A: Endocrine gland B: Exocrine gland (4x2) (8)

Life Sciences/P1 9 1.4 The diagra gram below represents qa reproductive strategy in a fish species. Male fish 1.4.1 Name the type of fertilisation shown in the above diagram. 1.4.2 Name the type of reproductive strategy used by the fish as shown in the diagram above. 1.4.3 State TWO visible ways in which the chances of fertilisation are increased. 1.4.4 Explain why there is no need for the fish eggs to be covered with a hard or leathery shell. Copyright reserved MDE/Septembe Nsc p ©2025 (1) (2) (6) Please turn over

Life Sciences/P1 1.5 The diagram below represents parts of th system. 1.5.1 1.5.2 1.5.3 1.5.4 Copyright reserved 10 NSC MDE/September 2025, human male reproductive Identify part C. Describe the common function of parts A and B. Name the type of gametogenesis taking place at D. Test results show that a man has a low sperm count. Explain why the doctor would advise the man not to put his laptop on his lap. TOTAL SECTION A: (1) (2) (1) (2) (6) 50

Life Sciences/P1 4 MDE/September 2025 NSC SECTION B QUESTION 2 2.1 The diagram below represents Parts of the human female reproductive system. A 7 B D ° Ly sg | E U F 2.1.1. Give the LETTER and NAME of the part, where sperms are deposited during copulation. (2) 2.1.2 Name the cell formed after the ovum and sperm have fused? (1) 2.1.3. State TWO functions of part B? (2) 2.1.4. Name the reproductive hormone responsible for the release of the ovum. (1) 2.1.5 Explain what happens to part D if fertilisation does not occur. (2) 2.1.6 Explain how cutting and tying of part A on both sides prevent fertilisation from taking place? (2) 2.1.7. Make a labelled drawing of the gamete released from part C. ne Pleasesturn over Copvriaht reserved

Life Sci iences/P1 an MDE/September 2025 2.2 The diagram below represents some changes that occur in the human female body during the menstrual cycle. The letters A to D represent hormones. Pituitary gland © oS Graafian follicle Endometrium days Li 0 14 28 (1) (1) 2.2.1 Identify hormone D. 2.2.2 Onwhich day of the cycle did ovulation take place? 2.2.3. Explain the negative feedback mechanism between hormones A and C if fertilisation occurs. ay Copyright reserved Please turn over

lite Sciences/P1 ‘s ha MDE/September 2025 he diagra i ; ee ae ee the circulation of blood in the uterus wall of a P » Ne arrows show the direction of blood flow. Foetal capillaries 4 > = Mother's blood \ sinuses —— = | Developing foetus = ae B A Circulation of blood in the uterus wall of a pregnant woman 2.3.1 Identify A. (1) 2.3.2 Explain ONE way in which the development of the foetus would be negatively affected should part B is tangled around the ankle. (2) 2.3.3 Tabulate TWO differences in the composition of the blood in the vessels found in structure B. (5) (8) Copyright reserved Please turn over

Life Sciences/P1 14 Bs MDE/September 2025 2.4 The flow diagram below represents osmoregulation in the human body. 2.4.1 2.4.2 2.4.3 2.4.4 Warm day Low intake of fluids and person is active | Receptors in hypothalamus j Gland A secretes ) hormone B | Effector C responds | Water level returns to normal _/ , / Define osmoregulation. (2) Name the organ responsible for osmoregulation? (A) Identify: (a) Hormone B (1) (b) GlandA (1) . i ; ®) Explain why a person may dehydrate if a tumour on gland A develops an Please turn over

Life Sciences/P1 15 MDE/September 2025 NSC 2.5 An oral glucose tolerance test is used to determine if a person is diabetic. ae rete foes ae (No food intake) the person drinks a glucose solution. glucose levels are then measured at regular intervals. The normal blood glucose level in the blood is 90mg/100ml. If the person’s blood glucose level is ab oe: : ove 200mg/100ml two hours after drinking the glucose solution then the patient is diagnosed as being diabetic. The results of a glucose tolerance test performed on three different patients (1, 2 and 3) is provided in the table below. ; : |___Blood glucose levels (mg/100m! Time (minutes) Patient? [Patient2 | Patient 3 O(glucose solution is ingested) 85 130 100 30 125 215 210 60 100 250 180 90 85 260 170 120 80 240 160 2.5.1 Identify the dependent variable in this investigation. (1) 2.5.2 Identify ONE factor that should be kept constant in this investigation. (1) 2.5.3 Explain why patients 1 and 3 were NOT diagnosed as diabetics. (2) 2.5.4 Explain how the blood glucose levels of patient 1 will return back to normal after 2 hours (2) (6) 2.6 Describe how the human body restores the carbon dioxide concentration in the blood when it is above normal levels. (6) (6) [50] Copyright reserved Please turn over

ET Gy Life Sciences/P1 Grade 12 learners carried out an inve ¢ force of gravity on the direction of growth of young roots (radicles) They set up the investigation as follows. Copyright reserved 16 NSC QUESTION 3 stigation to determine the effect of the of seedlings. e They placed six germinated seedlings onto the rotating disc of a clinostat as shown in diagram A. e They covered the seedlings on the clinostat with a wide-mouthed glass jar (A). : e They placed six germinated seedlings onto a cork disc as shown in diagram B. e They put the cork disc on its side and covered it with a wide-mouthed glass jar (B). e The seedlings were not rotated in B. They switched the clinostat in A on, so that the seedlings were continuously turning. They left the seedlings for two days. i im showi e effect of the force of gravity on the radicles of seedlin radicle clinostat wide-mouthed glass jar Cork disc radicle 3.1.1 Explain why the learners had to set up the rotating clinostat in diagram A? 3.1.2 What observation could be made in diagram B? 3.1.3 bic a conclusion, based on your observations in QUESTION 3.1.2 above. MDE/September 2025 (2) (2) (2) (6) Please turn over

MDE/sepie'~~" Life Sciences/P1 17 NSC 3.2 Read the extract below. Ghenene Mare (ee (CMT) disease is an inherited causes abnormalities i S alities in the nerves that supply your feet, mptoms. usually first appear in teens and young adults such as weakn lower_tég muscles. It is caused by genetic problem: protective lining around the axon. : Neurologist may diagnose CMT after doing a complete nervous system tic problems. There is exam through a blood or saliva test to look for gene no cure for CMT but physical therapy can help to strengthen and stretch your muscles. 3.2.1 Differentiate between a reflex action and reflex arc. (2) 3.2.2 From the extract, state the: (a) effect of Charcot-Marie-Tooth (1) (b) symptom of Charcot-Marie-Tooth (1) 3.2.3 Name the neuron responsible for carrying signals from the brain to the muscles. (1) 3.2.4 Name the part of a neuron that degenerates, leading to multiple sclerosis. (1) 3.2.5 Explain how damage to the part named in QUESTION 3.2.4 can lead to the symptoms of multiple sclerosis, as stated in the extract. (4) (10) Copyright Rae eyse: Please turn over

Life Sciences/P1 . . MDE/September 2025 3.3 The diagram below shows the side view of a human eye. 3.3.1 Give TWO functions of the following parts: (a) B (2) (b) © (2) 3.3.2 Explain how part A is adapted for its function. (2) 3.3.3 Describe the changes that occur in the eye when a person focuses on an object that is three metres away. Be Copyright anaes Please turn over

Life Sciences/P4 19 MDE/September 2025 NSC 3.4 The di SESS BS layp represents parts of the human ear. A B c 3.4.1 Identify part F. (1) 3.4.2 State ONE function of part D. (1) 3.4.3 How are parts A and B together suited for the amplification of sound? (2) 3.4.4 Explain why a rupture (hole) in part A may lead to hearing loss. (2) 3.4.5 Explain the result if part C is blocked with mucus. (2) 3.4.6 Describe how receptors in part E maintain balance (4) (12) Please turn over Copyright reserved

Life Sciences/P1 3.5 The table below shows the rec 20 MDE/September 2025 NSC orded number of people suffering from Alzheimer's disease in provinces in South Africa. Year Number of people suffering from Alzheimer’s disease 2021 40 2022 70 2023 90 2024 120 3.5.1 3.5.2 3.5.3 3.5.4 Copyright reserved Name TWO main symptoms of Alzheimer’s Disease? Explain why this data in the table may not be accurate for the provinces. Calculate the percentage increase of number of people suffering from Alzheimer's disease from 2021 to 2024. Draw a line graph to represent the data in the table. TOTAL SECTION B: GRAND TOTAL: (2) (1) (3) (6) (12) [50] 100 150